\documentclass[landscape]{article}
\setlength{\pdfpagewidth}{11in} \setlength{\pdfpageheight}{8.5in}
\begin{document}
\begin{tabular}{lcccccccc}
\multicolumn{9}{c}{Effect} \\
\multicolumn{9}{c}{)} \\ \hline
 & (1) & (2) & (3) & (4) & (5) & (6) & (7) & (8) \\
VARIABLES & changepop1400 & changepop1400 & Z & Z & changepop13001600 & changepop13001600 & Z & Z \\ \hline
 &  &  &  &  &  &  &  &  \\
mortality & -3.19*** & -2.38** & -0.069*** & -0.051** & -4.47 & -3.64 & -0.021 & -0.017 \\
 & [1.08] & [1.08] & [0.023] & [0.023] & [3.28] & [4.00] & [0.015] & [0.018] \\
nonlocal & -2.89*** & -2.23** & -0.062*** & -0.048** & -2.96 & -3.09 & -0.014 & -0.014 \\
 & [0.99] & [1.01] & [0.021] & [0.022] & [3.85] & [3.81] & [0.018] & [0.017] \\
interact & 0.06*** & 0.04* & 0.001*** & 0.001* & 0.11 & 0.09 & 0.000 & 0.000 \\
 & [0.02] & [0.02] & [0.000] & [0.000] & [0.09] & [0.10] & [0.000] & [0.000] \\
 &  &  &  &  &  &  &  &  \\
Observations & 160 & 165 & 160 & 165 & 159 & 164 & 159 & 164 \\
R-squared & 0.19 & 0.16 & 0.185 & 0.164 & 0.04 & 0.02 & 0.037 & 0.020 \\
 test & state & distance10pctil & state & distance10pctil & state & distance10pctil & state & distance10pctil \\ \hline
\end{tabular}
\end{document}
